Prevalence of neural tube defects in the Province of Quebec, 1992

A retrospective study of neural tube defect (NTDs) was carried our among elective terminations of pregnancies, stillbirths and live births to women residing in two: regions of Quebec, in 1992. Primary data: sources included the hospital administrative: data system MEDECHO, stillborn and infant death certificates, and the list of patients seen at three spina bifida clinics. Hospital records were reviewed. A total of 30 NTD cases were identified. The prevalence: rate was 1.41 per 1,000, indicating a three-fold reduction in frequency during the last, three decades. All 17 cranial defects but only; 5 of 13 spinal defects were diagnosed during pregnancy. Elective terminations were performed at an average gestation of 18 weeks (range 11 to 21 weeks). The MEDECHO file allows a complete identification of NTD cases, but diagnostic categories are not very specific and coding errors are present.